System and Method for Forming Artificial Turf Products with a Woven Appearance

ABSTRACT

A system and method for forming synthetic/artificial grass or turf tufted fabric materials in which a series of tufts or artificial/synthetic grass or turf yarns is formed in a backing material. The system generally will include a row of needles mounted along a tufting zone and which are reciprocated through the backing material to deliver a series of yarns into the backing materials. The needles are arranged in needle groups with the needle groups spaced apart along the length of the needle bar. A series of gauge parts, typically including cut-pile hooks, will be aligned with and will engage the needles in order to form cut and pile tufts defining spaced grass/turf tuft formations in the backing material.

FIELD OF THE INVENTION

The present invention generally relates to systems and methods for forming artificial/synthetic sports grass or turf fabric materials or products, and in particular to a method and system for forming artificial/synthetic sports grass or turf fabrics materials or products utilizing tufting systems and processes to form such grass or turf fabric materials or products with a woven appearance.

BACKGROUND OF THE INVENTION

Artificial/synthetic grass or turf products have been growing in popularity and demand in recent years, especially for use in indoor stadiums and in geographic areas where grass fields are difficult to maintain due to weather and heavy use conditions. In the past, such synthetic turf products typically have been formed by various methods, including being formed as woven products in which loops of synthetic turf filaments or fibers are woven into a mesh or backing material and the tips of the loops thereafter sheared to create the appearance of blades of grass. After the “grass” is formed, an infill material, such as crumb rubber, sand, and/or other particulate matter, generally is applied between the tufts of the synthetic grass filaments to help support and cushion the turf fibers/filaments. One problem with such woven turf products is a tendency of the turf fibers to flatten in the direction of the weave, especially over continued or extensive use and as the infill material is disturbed. This leads to a “corn-row” appearance that is less natural looking and tends to reduce the cushioning effects of the turf.

Synthetic turf or grass fabrics further generally must meet desired standards for cushioning, support, ball bounce, and the amount of infill material (i.e., crumb rubber, sand or other particulate matter) needed between the tufts to provide adequate support and cushioning, especially where the turf is installed in sanctioned athletic fields, such as for professional, college, and high school sports facilities. For example, FIFA, the governing body for international soccer has very specific standards for the amount of cushioning and support to be provided by the synthetic turf material when used for its fields, as well as for ball bounce and the amount of infill that can be used in such synthetic turf fields. There also understandably is a continuing need to try to improve the cushioning, support and playability of synthetic turf fields in order to improve the players' comfort and help reduce injuries as much as possible. This includes controlling, as much as possible, the amount of infill or particulate matter needed to support the synthetic turf or grass filaments, which particulate matter often gets in players' eyes, as it is disturbed during play, as well as the resiliency and upright appearance of the turf to avoid flattening and/or the appearance of “corn-rows” and/or gaps therein, especially as the infill material becomes disturbed.

SUMMARY OF THE INVENTION

Briefly described, the present invention generally relates to a system and method for forming artificial/synthetic grass or turf type fabrics with a substantially woven appearance utilizing a tufting process in which tufts of synthetic grass or turf type yarns, filaments or fibers are inserted into a backing material in dense groupings of synthetic turf stitch formations to form artificial/synthetic grass or turf products. The present invention generally is adapted to be utilized in a tufting machine including a row of needles positioned along a needle bar that extends laterally across the tufting zone of a tufting machine. Each of the needles generally includes a pick-up area and carries a synthetic grass or turf yarn for introduction into a backing material that is being conveyed longitudinally through the tufting zone.

In accordance with one embodiment of the invention, the needles are arranged in discrete needle groupings of one or more needles, typically at least two or more needles, with each of the needle groupings being spaced along the transverse length of the needle bar. Each of the needles within the needle groupings generally is spaced by a predetermined or predefined gauge or first spacing distance, for example, 3/16 of an inch, ⅛ of an inch, 5/32 of an inch, etc. Each of the needle groupings further is spaced from adjacent needle groupings at a second spacing distance that is a multiple of the first spacing distance between each of the needles of the needle groups, which multiple can be based upon the number of needles within each of the needle groups. For example, if each needle grouping includes two needles spaced 3/16 of an inch apart, the second spacing distance for each of the needle groupings generally can be approximately based upon the number of needles times the first spacing distance between each of the needles, e.g., two times 3/16 of an inch or approximately ⅜ of an inch.

A yarn feed system, typically having a series of driven yarn feed rolls, will feed a series of yarns to corresponding needles of the tufting machine. The yarn feed system also can include various pattern attachments such as a roll or scroll type pattern attachment, single end yarn feed control, etc., and to control feeding of desired amounts of yarns to each of the needles as the needles are reciprocated into and out of the backing material. A gauging element assembly is located below the tufting zone at an elevation selected for forming tufts of the yarns of a desired length so as to enable formation of grass or turf formations of a desired height when formed into the finished artificial/synthetic grass or turf product. The gauging element assembly generally will include a series of cut pile hooks, although other types of gauging elements including loop pile loopers, cut/loop clips, level cut loop loopers and combinations thereof also can be used, located at an elevation to engage the needles as the needles substantially penetrate the backing material. The gauging elements will pull the synthetic grass or turf yarns from the needles, thus forming loops of yarns, which thereafter generally can be cut to form cut pile tufts having an appearance or structure of grass.

Backing feed rolls are mounted at the upstream and downstream portions of the tufting zone of the tufting machine and control the feeding and tension of the backing material through the tufting zone. The backing feed rolls generally will be driven by one or more motors, such as servomotors, stepper motors, vector motors, AC motors, DC motors, and/or other, similar drives under control of a backing feed control system according to the principles of the present invention. The backing feed control system can include a separate control, but typically can be included as part of the tufting machine control system which controls the operative elements of the tufting machine, including yarn feed, backing feed, etc., based upon the operation of the main shaft of the tufting machine. The motors of the backing feed rolls will be monitored by the backing control system and the backing material indexed or advanced in accordance with the steps of a pre-programmed pattern for forming the artificial/synthetic grass or turf with a desired density so as to feed the backing material forwardly through the tufting zone at desired increments according to the pre-programmed stitch rates.

With the backing feed control system according to the present invention, the yarn feed and backing feed of the tufting machine will be controlled so as to provide for the formation of tufts of synthetic/artificial grass or turf type fibers or yarns arranged in dense groupings of stitch formations or tuft groups that are spaced from one another across and along the length of the backing material. In particular, as the backing material is fed through the tufting zone, the movement of the backing material will be controlled by the backing feed control system so that a series of stitches will be placed substantially inline, with the stitches being arranged at a first stitch length distance, which can be approximately the same as the first spacing distance between the needles of each grouping of needles. After a desired number of stitches are planted into the backing material at the first stitch length, if the next stitch requires a jump of the backing, the backing material will be further indexed by a second stitch length, based upon the first stitch length plus a calculated jump distance. For example, the second stitch length can be approximately equivalent to the second spacing distance between each of the needle groupings. Thereafter, the pattern can be continued with additional stitches being placed at the first stitch length to form additional dense groupings of stitch formations, with infill areas or areas of separation defined therebetween as a result of the jumps or movement of the backing material by the second stitch length. The infill areas further generally can be substantially uniform in all directions (i.e., approximately 360°) about each dense tuft group, providing areas in which a infill material can be received to support the artificial/synthetic grass or turf yarns as understood by those skilled in the art.

The backing feed control system further typically will monitor the position of the main shaft so as to determine when the needles are leaving the backing material or are at a desired position out of or nearly out of the backing material so as to begin advancement of the backing material and complete the advancement or indexing thereof in sufficient time prior to the needles finishing a downward stroke. The control system also can slow or delay/stop the movement of the backing material as the needles penetrate the backing material to form the tufts of grass or turf yarns as part of such control. In addition, a shift mechanism can be provided to control/cause a transverse movement of the needles as needed to further help avoid “rowing” effects in the finished artificial/synthetic grass or turf fabric material or product.

The backing feed control system and method of the present invention accordingly will enable the formation of artificial/synthetic grass or turf products utilizing a tufting process and having a substantially woven appearance of dense tuft groups arranged in a balanced, spaced arrangement both laterally across and longitudinally along the length of the backing material. As a result, improved and/or more precise distribution of tufts of the synthetic grass yarns can be provided across the backing material, enabling less yarn weight while providing better support for the tufts against flattening or laying down to avoid rowing effects and provide an enhanced natural grass appearance and feel to the finished artificial/synthetic grass or turf product.

Various objects, features and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description, when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is front view of a tufting machine utilizing a system for controlling the backing feed to form an artificial/synthetic grass or turf tufted fabric material according to the principles of the present invention.

FIGS. 2A and 2B are side elevational views of the tufting machine of FIG. 1, schematically illustrating the reciprocation of the needles into the backing material for the formation of the desired spaced, dense tuft groups and infill areas therealong.

FIG. 3A is a side elevational view illustrating the sewing of the tufts of synthetic grass or turf yarns into the backing material by the needles according to the method of the present invention.

FIG. 3B is a top plan view of one example embodiment of a pattern of dense groupings of stitch formations or tuft groups of synthetic grass or turf yarns with infill areas defined thereabout utilizing the system and method of controlling the backing feed to form artificial/synthetic grass or turf tufted fabric materials according to the principles of the present invention.

FIG. 4 is a flow diagram illustrating the method of controlling the backing feed for forming an artificial/synthetic grass or turf tufted fabric materials according to the principles of the present invention.

FIGS. 5A and 5B are perspective illustrations of the top and bottom sides of an artificial/synthetic grass or turf tufted fabric materials formed according to the principles of the present invention.

Those skilled in the art will appreciate and understand that, according to common practice, various features and/or components of the drawings as discussed below are not necessarily drawn to scale, and that the dimensions of various features and elements shown in the drawings and discussed in the following detailed description may be expanded or changed to more clearly illustrate the embodiments shown therein without departing from the principles of the present invention as described herein.

DETAILED DESCRIPTION OF THE INVENTION

Referring now in greater detail to the drawings in which like numerals indicate like parts throughout the several views, as illustrated in FIGS. 1-2B, according to an example embodiment, the present invention is directed to a system 10 and method for controlling the movement of a backing material 11 through a tufting machine 12. The system and method of the present invention is designed to produce tufted artificial/synthetic grass or turf fabric products or materials that have an enhanced natural grass/turf, such as providing the artificial/synthetic grass or turf tufted fabric products or materials with a woven look or appearance, as opposed to a traditional tufted appearance, without requiring highly specialized machinery for producing artificial/synthetic grass or turf tufted fabric products or materials. The resultant artificial/synthetic grass or turf tufted fabric materials T accordingly are formed with a series of dense groupings of stitch formations or tuft groups 29 (FIGS. 1, 3A-3B, 5A-5B).

As generally indicated in FIGS. 1 and 2A-2B, the backing feed control system 10 can be mounted on or included as part of a computer control system for the tufting machine 12, generally indicated at 13, such as a “Command Performance” tufting machine computer control system manufactured by Card-Monroe Corp) Such a tufting machine control system 13 will include a computer controller or processor 14 that can be programmed with pattern information for forming various desired tufting patterns. The controller 14 will be in communication with and can be programmed to control various operative features and functions of the tufting machine, including monitoring and controlling one or more motors 15 driving the main shaft 16 of the tufting machine. An encoder 17 (FIG. 1), such as an absolute encoder, incremental encoder, resolver or similar monitoring device, generally will be mounted on the main shaft 16 for detecting and providing feedback information regarding the position of the main shaft during rotation thereof. Additionally, the controller system typically will include a user interface (not shown) such as a touch screen, keyboard, and mouse, tablet, or other similar input device to enable operator input and programming of the controller 14. The control system 13 further can be connected to a separate pattern design center or can include pattern design functionality or capability to enable creation and programming of patterns therein.

As indicated in FIGS. 1 and 2A-2B, the tufting machine 12 used with the present invention generally will include a frame 18 on which the main shaft 16 and drive motor 15 are supported for reciprocally driving at least one needle bar 19 (FIG. 1). In accordance with the present embodiment of the invention, the needle bar 19 typically carries a single laterally/transversely extending row of parallel needles 21 arranged in spaced groupings of needles 22 (FIGS. 1 and 3A). Each needle grouping 22 generally will include at least one needle 21, and in other embodiments, such as illustrated in FIG. 1, can include two, three, four or more needles within each needle grouping. The needles within each needle grouping generally will be spaced from the adjacent needles of their needle group by a first needle spacing, with each of the needles within each needle group generally being substantially uniformly spaced from their adjacent needles at a first spacing distance based on a selected gauge or combination of gauges for the tufting machine. For example, the first spacing distance between the needles of each needle group could be approximately 1/16″, 3/16″, 5/32″, ⅛″, ¼″, etc., from the adjacent needles, or other varied, desired spacings/gauges within each needle group, as will be understood by those skilled in the art. Alternatively, the needles within each needle group could be arranged at varying spacings as needed or desired to provide further variation to the tufts 28 of synthetic grass yarns making up each tuft group 29.

Each of the needle groups 22 further will be spaced from adjacent needle groups, as indicated in FIG. 1, by a second spacing distance, so as to define gaps 23 between each of the spaced needle groups extending across the needle bar. The second spacing defined between each of the needle groups generally can be based upon a multiple of the first spacing. As an example, this second spacing distance can be based upon the first spacing distance multiplied by the number of needles within each needle group. Thus, if each needle group 22 includes two needles 21 that are separated by a first spacing distance of 3/16 inch, the second spacing distance can be approximately 3/16 inch times the number of needles (2), or approximately ⅜ inch. Other, larger or lesser spacing distances also can be provided so as to define the gaps or spacings between each of the needle groups as needed to help further control the density and spacing between each of the tuft groups 29 formed within the finished artificial/synthetic grass or turf fabric materials. As an alternative example, the needles 21 within the needle groups could be at spacings of 3/16 inch, or at other, varying spacings, while the needle groups could be spaced from each other at a multiple of 2, 3, 4 or other multiples, unrelated to the pitch or number of needles in the group, (e.g., there could be only 1 needle per group, or more needles in each group), such as being arranged at spacings of about ¾-½ inch, or other desired spacings not related to the gauge of the needles. The gaps 23 thus defined between the needle groups help provide improved tuft distribution across the face of the backing material for a more natural grass/turf look and feel.

In addition, a shift mechanism 20 (FIG. 1) can be provided, linked to the needle bar 19 for shifting the needle bar laterally, in a direction transverse to the longitudinal movement of the backing material through the tufting machine (as shown by arrow B in FIGS. 2A-2B). The shift mechanism can include a cam or “Smart Step”™ shift control mechanism manufactured by Card-Monroe Corp., or other, alternative shifting mechanisms so as to impart a desired transverse or lateral motion to the needle bar. While shifting of the needles is not necessarily required, such shifting motion can be utilized to produce pattern effects as needed, in the finished artificial/synthetic grass or turf fabric materials. Alternatively, the shift mechanism can be utilized to provide a discrete side-to-side shifting motion to the needles as they are reciprocated into and out of the backing material so as to perform a “positive-stitch-placement” (“PSP”) type movement or operation to the needles (as shown and described in U.S. Pat. No. 4,630,558, the disclosure of which is incorporated herein as if set forth in its entirety) so as to provide variations in the tuft distribution of the synthetic grass or turf yarn tufts within each of the dense tuft groups 29 to further help reduce or substantially minimize potential rowing effects in the finished artificial/synthetic grass or turf fabric materials.

As indicated in FIGS. 1-2B, a tufting zone 24 is defined within the space below the needles 21, with the backing material 11 passing through the tufting zone in the direction of arrow B. As the needle bar is reciprocally driven by the main driveshaft, the needles 21 are moved between the vertically raised positions, out of engagement with the backing material, as illustrated in FIG. 2A, to a lowered position penetrating the backing material for inserting yarns 26 therein, as illustrated in FIG. 2B. The yarns 26 are fed to each of the needles 21 of the needle bar and are carried by their respective needles into and through the backing material to form tufts 28.

As previously noted, the yarns 26 generally will be synthetic grass or turf type fibers, filaments or other, similar yarns. Such synthetic grass or turf yarns can include wrapped mono-filament turf yarns having a series of turf fibers or filaments wrapped within a sheath or filament, fibrillated ribbon type yarns or various other synthetic turf or grass type yarns or fibers as commonly used for the manufacture of artificial/synthetic grass or turf fabric materials as will be understood by those skilled in the art. Additionally, while the yarns typically will be of a color and/or texture designed to approximate as closely as possible a natural grass or turf, it also will be understood that the yarns can be formed in other colors and with other textures or performance features as need or desired for the particular end application, for example, with certain yarns being of different or varying colors to enable the tufting of pattern designs or other effects within the artificial/synthetic grass or turf fabric materials.

As shown in FIG. 2B, a gauging element assembly 30 is mounted below the tufting zone 24 and bed or needle plate 32 of the tufting machine. The gauging element assembly includes a series of cut pile hooks 31 or other gauge parts that are located at an elevation for forming a desired pile height of the synthetic grass or turf yarns, and are movable, as indicated by arrows 33/33′ into engagement with the needles 21 as the needles penetrate the backing material 11, striking the needles and pulling loops of the yarns 26 therefrom to form the tufts 28 of synthetic grass or turf yarns of the tuft groups 29 (FIGS. 3A and 3B and 5A-5B). The gauge parts also could include loop pile loopers, both loop pile loopers and cut pile hooks, as well as cut/loop loopers, or level cut loop (“LCL”) loopers that include a controlled pattern reciprocating looper with a clip therealong and/or combinations thereof.

Each cut pile hook 31 generally will include a hook body 34 having a hooked front end or bill 35 for picking up and retaining loops of yarns from their corresponding needles 21, as illustrated in FIG. 2B. The body of each cut pile hook 31 will be mounted in a holder or support 36 attached to a reciprocating drive 37 that reciprocates the cut pile hooks toward and away from engagement with the needles 21. Knives 38 are reciprocated into engagement with the cut pile hooks to sever the loops of yarns 26 retained on the hook bodies 34 to form the cut pile tufts 28 which approximate blades of grass of the artificial/synthetic grass or turf fabric material T.

As further illustrated in FIG. 1, the yarns 26 generally will be fed through a yarn feed system 40 from a yarn source 41 to each of the needles 21 and 22. The yarn feed system 40 generally will include a series of yarn feed rolls 42 that can be driven by one or more drive motors 43 (such as a servo or stepper motor, vector motor, AC motor, DC motor or other drive motor) under the control of the computer 14 of the tufting machine control system 13. However, a single drive motor 43 also can be used for driving at least one of the yarn feed rolls directly, with the remaining yarn feed/puller rolls being driven off the servo driven yarn feed roll. In addition to the control of the movement of the backing material 11, the yarn feed system also can communicate with and be controlled by the computer 14 of the tufting machine control system to control of the operation of the yarn feed puller rolls to feed more or less yarns for a desired stitch of a preprogrammed pattern to provide additional patterning effects such as high/low or sculptured effects.

Still further, the yarn feed system 40 can include various pattern attachments such as servomotor driven yarn feed rolls, electro-mechanical or air operated clutches, single or double/dual yarn feed systems, and/or servo driven roll or scroll type pattern attachments, including single end scroll attachments, such as the systems disclosed and claimed in co-owned U.S. Pat. Nos. 6,807,917 and 6,834,601, the disclosures of which are incorporated by reference as if set forth fully herein, and other pattern attachments such as a Yarntronics or Quickthread pattern attachment as manufactured by Card-Monroe Corp, which can be used with the system and method of the present invention to provide further patterning variations and effects.

The backing feed control system 10 of the present invention further includes backing or cloth feed rolls 45 and 46 mounted at the front or upstream edge 47 and the rear or downstream edge 48, respectively, of the tufting zone 24 of the tufting machine 12, as indicated in FIGS. 2A-2B. Each of the backing feed rolls 45 and 46 generally will be controlled/driven by a motor 49 or 51, respectively, that communicates with and is controlled by the computer 14 of the tufting machine control system 13. The motors 49 and 51 typically are servomotors, although other variable speed motors, such as stepper motors, vector motors, AC motors, DC motors, and/or other type actuators or drive systems also can be used. In addition, as further indicated in FIG. 1, gear boxes 52 also can be used for assisting in the driving of the backing feed rolls 45/46 by their drive motors 49/51 to provide a desired gear reduction or drive ratio as needed. It further will be understood that while a pair of motors 49 and 51 are shown for driving each of the backing feed rolls 45 and 46 (FIGS. 2A-2B) respectively, it is also possible to utilize one motor, such as either motor 49 or motor 51 for driving either the front or rear backing feed roll, with the other backing feed roll being driven by belt drive or other linkage connecting it in a driven relationship to the motor controlled/driven backing feed roll. It further is possible to use a rotating mechanical cam system that advances the backing at a first stitch length for a desired number of stitches/tufts and thereafter causes the backing material to move an additional advancement distance or jump. The driving of the backing feed rolls will be controlled in order to maintain tension control to the backing material 11 as it is fed through the tufting zone in the direction of arrow B, as well as to cause a “jump” or advancement of the backing material as needed to form desired pattern effects in the tufted article being manufactured.

In addition, the backing feed control system of the present invention further can be used in conjunction with additional pattern devices or systems, as discussed above, such as using one or more shifting needle bars in place of the needle bar 19 (FIG. 1), and/or the use of opposite hand loopers and cutting, as disclosed in U.S. Pat. No. 6,834,602, the disclosure of which is incorporated herein. It is also possible to use servo driven puller rolls as discussed above, as well as servomotor driven pattern attachments that include one or more servo motor driven yarn feed rolls, electromechanical clutches, single or double yarn feed roll systems, and/or even single end yarn feed control systems or attachments. Still further, the backing feed control system further can be intermixed with conventional or regular stitches in an alternating fashion, and with the needles being shifted as needed to form programmed pattern effects/stitches between the jumps of the backing material for the formation of pattern elements or effects by the backing control system.

In operation of the backing feed control system 10 (FIG. 1) of the present invention, the computer 14 of the tufting machine control system 13 generally will be programmed with a desired or prescribed first stitch length, taking into account the first spacing distance or the gauge of the needles 21 of the needle groups 22, i.e., for a machine set up having a first spacing distance of 3/16″, the stitch length generally likewise can be approximately 3/16″, although a variety of greater or lesser desired first stitch rates or lengths can be used as needed or desired to vary the placement of the tufts 28 of synthetic grass or tuft yarns. The pattern also can be organized into stitch cycles or repeats of generally two to four stitches per cycle, although more or less stitches per cycle also potentially could be used.

In addition, the movement of the backing feed is generally made according to a stitch or backing feed profile determined by: (1) the first stitch length of at least the initial stitch in the current stitch cycle of the pattern, and for any subsequent stitches in that stitch cycle the first stitch length and, if needed or called for, any calculated jump distance or additional advancement/indexing of the backing feed required (which could be equal to zero where no jump or additional indexing is required); and (2) the percentage of first backing material advance allowed versus main shaft rotation (i.e., the backing material could be limited in its movement to only when the needles are out or nearly out of the backing material, which could be approximately 30-40% of the time for a single rotation of the main shaft, with the backing material staying constant, being paused, or slowed to a desired rate, the remaining percent of the time). As a further alternative, the backing feed movement can include a phase advance setting based upon the rotation or position of the main shaft, whereby the computer can initiate the operation of the servomotor(s) or drives controlling the movement of the backing material as (or immediately prior to) the needles are being moved out of the backing material to their raised, non-engaging position.

FIG. 4 illustrates the general cycle of operation according to at least one embodiment of the present invention. At a first step 100, a first spacing distance, corresponding spacing between the needles of the needle groups, and at least one second spacing distance, corresponding to the gaps between the needle groups, are set and input into the computer operating the backing feed control system of the invention. If the needles of each needle group are set at a first spacing distance of 3/16inch, the needle groups formed thereby generally can be spaced at a multiple of the first spacing. In one example embodiment, this second spacing can be set/determined based on a number of needles of each needle group, i.e., for 2 needles, the second spacing distance can be approximately ⅜ inch; for 3 needles, approximately 9/16 inch; for 4 needles, approximately ¾ inch, etc., although alternative multiples not based on the number or gauge of the needles (e.g., 3 or 4 for a second spacing distance of about 9/16inch-¾inch) also can be used.

Thereafter, as the pattern or each stitch cycle or repeat thereof is commenced at step 101, the computer of the tufting machine control system will monitor the operation of the main shaft of the tufting machine, such as via the encoder on the main shaft or other, similar measuring device measuring incremental position or rotation of the main shaft, as well as monitor the backing feed and yarn feed motors as noted at 102. The main shaft is monitored to determine the position of the needles during each stroke so as to determine whether the needles are at any given point in the formation of a stitch (i.e., as the needles penetrate the backing material and when the needles are moving out of the backing material), indicated at 103. During the next step(s) or stitches of a stitch cycle, as shown at 104, as the needles are removed from the backing material, the backing material typically is indexed longitudinally a distance approximately equal to the programmed first stitch length for sewing the next stitch in the pattern. For example, for a first needle spacing of 3/16″, the backing material can be indexed or incremented forwardly by a first stitch length/distance of about 3/16″ to move the backing material to an initial position for sewing of a next stitch.

In addition, during the stitch forming operation/step, as the needles penetrate the backing material, the feed or longitudinal movement of the backing material through the tufting zone may be slowed, or it is also possible that the movement of the backing material can be, paused or delayed as the needles penetrate the backing material to prevent tearing of the backing material and/or breaking of the needles. As also noted, the backing feed control system further can be programmed with a phase advance setting to begin the indexing of the backing material at substantially the same time, or even just prior to, the needles being moved out of the backing material to ensure there is sufficient time between the needles leaving and re-penetrating the backing material during a needle stroke or cycle to move the backing material the desired amount of advancement with the potential engagement and tearing of the backing material or damage to the needles due to movement of the backing material with the needles inserted therein being minimized.

The computer then will check the pattern information for the next stitch to be sewn in the pattern (106) to determine whether or not the next stitch would require movement/indexing of the backing material by the second stitch length, necessitating a jump or movement of the backing material by an additional advancement distance, in addition to the first stitch length, as indicated at 107. This check can be done at about the same time as the backing is being indexed or can be done a desired number of stitches in advance so that the jump or additional movement to index the backing material by the second stitch length, if required, can be accounted for by beginning the movement of the backing material as soon as possible during the needle stroke cycle. If the next stitch of the pattern requires the backing material to be indexed only by the proscribed stitch length, i.e., no jump or additional movement is required (arrow 108), the system repeats/continues its cycle of inserting the needles into the backing material to form tufts of yarns 28 (FIGS. 5A-5B), followed by the indexing of the backing material 11 according to the first or second stitch length of the next stitch being sewn in the pattern cycle.

If the next stitch of the pattern is to be at the second stitch length, so as to require a jump or additional advancement distance of the backing material (shown by arrow 109 in FIG. 4), the backing material generally is indexed forwardly, longitudinally by the distance of the first stitch length of the next stitch in the pattern, plus a calculated jump or advancement distance as indicated at 111. For example, during a two stitch cycle of the programmed dense tuft group formation pattern, the linear motion of the backing material may advance 3/16 inches for a first and second stitch, and thereafter advance approximately ⅜ inches ( 3/16 inches plus a “jump” of 3/16 inches) for the next stitch of the pattern. These “jumps” or additional increments of the backing material, together with the gaps defined between each of the needle groups help define open infill areas, spaces or regions 60 (FIGS. 3B, 5A-5B) that substantially surround, i.e., extend about 360° around each of the dense tuft groups 29. When a granular infill material later is applied to the artificial/synthetic grass or turf fabric material, these infill areas can help facilitate the infill material substantially flowing around, as well as in between, the tufts 28 of the tuft groups to provide better support on all sides of the tufts.

Thereafter, the system continues to run successive stitch repeats or cycles of the pattern (as indicated by step 112) until the desired run length of carpet to be produced has been completed (113), after which the pattern run or tufting operation can be ended (114) and the system can be shut down.

The method of the present invention accordingly enables one or more consecutive, inline, longitudinally extending rows of tufts 28 of synthetic grass or turf yarns (FIGS. 3A-3B) to be formed across the face of the carpet using the same inline rows of needles, with these tufts 28 arranged in spaced, discrete dense groupings of stitch formations or tuft groups 29, and generally without the yarns from other rows of needles being intermixed between such consecutive longitudinal rows as generally shown in FIGS. 3A and 3B. Other formations/groupings in which the tuft groups are staggered or off-centered also can be used. These spaced dense groupings of tufts 29 or stitch formations provide for improved tuft distributions along and across the face of the backing material as shown in FIGS. 3A and 5A-5B that further can enable greater tuft distribution with less yarn weight required.

Additionally, the arrangement and spacing of the individual tufts 28 within the groups 29 can provide support for the adjacent tufts of each tuft group to help resist laying over or collapsing of the individual tufts that might create rowing effects. The dense tuft groups furthermore are substantially surrounded by open infill areas or spaces 60 of a desired size to enable a substantially surrounding (e.g. approximately 180°-360° about the tuft groups) pattern of the infill material to provide support to the tufts. These synthetic grass yarns within these dense tuft groups or clusters of cut pile grass yarn tufts can spread while retaining support from neighboring tufts and surrounding infill material, with the amount of infill required potentially being reduced while still providing a desired level of support to the tufts, to thus present an appearance and feel closer to natural grass/turf. As a result, with the method of the present invention, artificial/synthetic grass or turf fabric materials having a “woven” look can be produced, with the resultant artificial/synthetic grass or turf fabric materials generally being substantially balanced both end-to-end and edge-to-edge, and with the tuft groups being placed with more precision and less buried ends, which can help enable lower weight and more resilient and natural looking/feeling artificial/synthetic grass or turf fabric materials to be produced.

The foregoing description of the present invention illustrates and describes various embodiments, without limitation, for forming an artificial/synthetic tufted grass or turf fabric product. It will be understood that various changes can be made to the above-described constructions and embodiments, without departing from the spirit and scope of the present invention, and it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. Furthermore, the scope of the present invention covers various modifications, combinations, alterations, etc. of the above-described embodiments of the invention.

Additionally, while the present disclosure shows and describes selected embodiments of the invention, it will be understood by those skilled in the art that various other combinations, modifications, changes and environments/operative conditions and uses of the present invention further are within the scope of the present disclosures as expressed herein, commensurate with the above teachings and/or within the knowledge or skill of the relevant art. Accordingly, it will be understood that certain features and characteristics of each embodiment disclosed herein may be selectively interchanged, modified, and/or applied to other illustrated and non-illustrated embodiments of the present invention without departing from the spirit and scope of this invention. 

What is claimed is:
 1. A tufting machine for tufting an artificial turf/grass product comprising: backing feed rolls; a drive system for controlling operation of the backing feed rolls, including at least one motor driving at least one backing feed roll for feeding a backing material through a tufting zone of the tufting machine; a needle bar having a series of needles mounted therealong, wherein the needles are arranged in spaced needle groups, with the needles of each needle group arranged at a first spacing distance and with the needle groups being spaced apart by a second spacing distance; a yarn feed mechanism for feeding synthetic turf yarns to the needles of the needle bar; and wherein the drive system controls the at least one motor so as to index the backing material longitudinally at varying distances to form dense groupings of stitch formations of the synthetic turf yarns in the backing material, with selected infill regions defined thereabout.
 2. The tufting machine of claim 1, wherein each needle group comprises at least two needles.
 3. The tufting machine of claim 2, wherein the second spacing distance between each needle group is defined by the first spacing distance between the needles of each needle group multiplied by a number of needles in each needle group.
 4. The tufting machine of claim 1, wherein the first spacing distance of the needles of each needle group is approximately 3/16 inch.
 5. The tufting machine of claim 4, wherein the second spacing distances comprise a multiple of 3/16 inch.
 6. The tufting machine of claim 4, wherein each needle group comprises 2 needles, and the second spacing distance is approximately ⅜ inch.
 7. The tufting machine of claim 1, and further comprising a shift mechanism for controlling lateral movement of the needle bar.
 8. The tufting machine of claim 1, and further comprising a series of gauge parts aligned with and adapted to engage the needles as the needles penetrate the backing material.
 9. The tufting machine of claim 8, wherein the gauge parts comprise cut pile hooks.
 10. A method of forming an artificial or synthetic turf/grass product on a tufting machine having a needle bar with a series of needles arranged in spaced needle groups mounted therealong, comprising: a. feeding a backing material through a tufting zone of the tufting machine; b. reciprocating the needles into the backing material to form a series of tufts of turf fibers in the backing material; c. indexing the backing material longitudinally by a first stitch length; d. reciprocating the needles into the backing material to form a next series of tufts of turf fibers in the backing material; e. if the backing material is to be indexed further longitudinally by the first stitch length, repeating steps c. and d. to form tuft groups at spaced locations along and across the backing material; f. if the backing material is to be indexed further longitudinally by a second stitch length, indexing the backing material longitudinally by the first stitch length plus an additional advancement distance; and g. repeating steps b.-f. until a desired amount of the artificial or synthetic turf/grass product has been formed.
 11. The method of claim 10 and wherein the second stitch length is greater than the first stitch length.
 12. The method of claim 10 and wherein the first stitch length is approximately equivalent to a spacing between the needles of each needle group, and the second stitch length is determined based upon the first stitch length multiplied by a number of needles in each needle group.
 13. The method of claim 10, wherein indexing the backing material by a second stitch length comprises moving the backing material a distance approximately equivalent to a spacing distance between the needles of each needle group.
 14. The method of claim 10, further comprising setting needle group spacings along the needle bar.
 15. The method of claim 14, further comprising forming infill areas between the tuft groups, each infill area of a size approximately equivalent to the needle group spacings.
 16. The method of claim 14, wherein the first stitch length is approximately equivalent to a spacing between the needles of each needle group and the second stitch length is approximately equivalent to a needle group spacing.
 17. The method of claim 16, wherein a infill area of a desired size is formed about each of the dense tuft groups, and further comprising applying a infill material within each infill area.
 18. The method of claim 10, wherein each of the needles of the needle groups is spaced from an adjacent needle of its needle group at a first spacing distance, and each needle group is spaced from an adjacent needle group by a second spacing distance comprising a multiple of the first spacing distance multiplied by a number of needles in each needle group.
 19. The method of claim 18, wherein each needle group comprises 2 needles, the first spacing distance is approximately 3/16″, and the second spacing distance is ⅜″.
 20. The method of claim 18, wherein infill areas, each of a size approximately equivalent to the second spacing distance, are formed about each of the dense tuft groups. 